The present invention relates to a mounting system for a pedestal crane having a rotational crane gantry.
A pedestal crane has a revolving gantry including a boom mounted on a support pedestal. A mounting system for mounting the gantry to the pedestal typically includes a bearing assembly which provides for rotation of the gantry about the pedestal and transmits to the support pedestal forces imposed upon the crane gantry by loading of the boom.
Pedestal crane mounting systems have utilized thrust and radial bearings. In some known systems, the thrust bearing is of a planar, circular configuration and made of a nylon material. The radial bearing is similar to the thrust bearing, also being of a planar, rectangular configuration and made of a nylon material. An example of this type of pedestal crane mounting system is that shown in U.S. Pat. No. 4,184,600, issued to Goss et al. on Jan. 22, 1980.
Another pedestal crane mounting system heretofore used includes a cylindrical bushing, preferably of brass, carried on a support column extending upwardly from the end of the pedestal. The mounting system further includes first and second arcuate sections disposed in spaced-apart relation above the bushing to provide vertical support of the crane gantry. Rollers are also mounted on the crane gantry to facilitate rotation of the gantry abut the pedestal. An example of this type of pedestal crane mounting system is that shown in U.S. Pat. No. 4,061,230, issued to Goss et al. on Dec. 6, 1977.
In yet another pedestal crane mounting system heretofore used, there is utilized a bearing assembly having an inner race fastened to the support pedestal, an outer race secured to the crane gantry and three sets of rollers inserted between the races. The three sets of rollers include two sets providing upper and lower thrust bearings and one set providing a radial bearing. An example of this type of pedestal crane mounting system is that shown in U.S. Pat. No. 4,216,870, issued to Bonneson et al. on Aug. 12, 1980.
With pedestal crane mounting systems of the foregoing types, removal of the bearing assembly for inspection or replacement is difficult. Accordingly, there is a need for an improved pedestal crane mounting system providing for the inspection and replacement of the bearings in a simple and easy operation.